The Sir William Osler Collection, distinct from the Bibliotheca, is an extensive archival holding of Osler's correspondence (including eighteen hundred original letters), daybooks, accounts, engagement books, legal documents, book invoices, membership certificates, notebooks, lectures, addresses, newspaper clippings, photographs, books with manuscript additions, and miscellaneous loose items formerly inserted into individual books in his library. The collection also contains various family papers, including correspondence of Lady Grace Revere Osler and Edward Revere Osler.

Fonds contains five notebook kept by medical student S. J. Bennett while studying at McGill University's Faculty of Medicine. Each notebook is devoted to a subject of study, including one notebook each labelled "Medicine", "Bacteriology" and "Obstetrics" and two notebooks labelled "Pathology." The notes inside are dated between 1907 and 1908. The notes are organized in some cases by instructor and in some cases according to medical conditions.

The fonds consists chiefly of student notebooks kept by F. Clarke Fraser while an undergraduate at Acadia University during the late 1930s-1940. They represent a variety of subjects, including zoology, physics, mathematics, and biology. Two notebooks date from his Med IV year (1949-1950) at McGill University’s Faculty of Medicine, one with ophthalmology lab and clinical notes and reading and lecture notes, and one an obstetrical diary from the Montreal Maternity Hospital. Also included is a later reprint of an article (published 1957), loose notes, and a photograph of F. Clarke Fraser and a companion dining at the Montreal restaurant Au lutin qui bouffe, famous for its resident piglet, which restaurant-goers were often photographed holding and feeding.